Weasleys, Prewetts, and the Black Family Tree

We got some illuminating comments about my recent work on Fred and George’s page. They raised several “Weasley” issues, mainly ones having to do with Prewett and Weasley names on the Black Family Tree — so I’ve been revising all of the Weasley pages to clarify what is canon and what is guesswork.

Canon:

Arthur was one of three brothers and had no sister. We don’t know his brothers’ names.

Molly’s maiden name was Prewett and she had at least 2 brothers, Gideon and Fabian. We don’t know if Molly had sisters; none are ever mentioned.

Ron (and by extension Bill, Charlie, Percy, Fred, George and Ginny) had an uncle Bilius, an aunt Muriel and a grandfather who played Wizard Chess. In addition to uncles Gideon and Fabian, of course.

Ginny is the only Weasley girl for generations.

Molly refers to a relative as “Our Great Auntie Muriel.”

Molly and Sirius are “cousins by marriage.”

Therefore, Molly’s parents are probably closely related to the ‘Ignatius Prewett’ listed on the Black Family tree. If the Black Family tree Jo drew is complete, Ignatius and Lucretia cannot be Molly’s parents themselves because they are indicated as being childless.

Arthur is “something like” Sirius’s second cousin once removed. This describes a relationship where one person’s great-great grandparent is the same person as the other person’s great grand-parent.

Therefore, Septimus Weasley is Arthur’s father. Septimus’s children would indeed Sirius’s second cousins once removed. Assuming the Black family tree Jo drew is complete, this relationship fits the facts and can be explained no other way.

Guesswork (not canon):

Edit: Auntie Muriel (HBP14, 29) is a member of the Prewett family. Not canon: We know neither Arthur nor his father had sisters, but any wife of their brothers would also be an aunt. “Auntie” can also be an honorary term. Aunt Muriel (whose goblin-made tiara Molly offers to Fleur) is probably a Prewett, but this cannot be canon without more information (thanks to ‘Reader2’ for pointing this out).

Bilius was one of Arthur’s 2 brothers. Not canon: We don’t know Bilius’s surname and we don’t know if Molly had more than 2 brothers. “Uncle” can also be an honorary name given to non-family members.

The grandfather who gave Ron the chess set is Septimus Weasley, Arthur’s father. Not canon: We don’t know his surname, so it could have been either Arthur’s father Septimus, or Molly’s father.

Thanks to Bel, John, Reader2, Marco, and Julie Stevenson for their helpful comments!